Voice over Internet protocol (VoIP) allows telephone calls to be made from any location around the world via a VoIP network such as the Internet. Users make and receive telephone calls via a VoIP network by connecting portable VoIP devices to the VoIP network, where each VoIP device operates as an interface between a telephone and a VoIP network. As referred to in this disclosure, a VoIP device may be any reasonably suitable device that converts analog audio signals into data packets and vice versa and communicates the analog audio signals and the data packets through an analog audio port and a data packet port, respectively. An analog terminal adapter (ATA) and a multimedia terminal adapter (MTA) are examples of VoIP devices.
As referred to in this disclosure, data packets each comprise a header field and a data field, where the header fields are used for processing data packets and may each include at least one of a source Internet protocol (IP) address, a destination IP address, a time, and any other data related to processing of data packets including cyclic redundancy check (CRC) bits.
As to a specific example of how a VoIP device is used, a user of the VoIP device may first sign up for a VoIP service through a service provider, where the VoIP device may have an assigned telephone number. The user may make and receive telephone calls through the assigned telephone number regardless of where the user is located around the world by accessing a VoIP network using the VoIP device. Users may plug one or more telephones into a VoIP device, and the telephones will operate, usually transparently, on the VoIP network.
Recently, use of VoIP telephone service has been gaining popularity over telephone calls made through a plain old telephone service (POTS). One of the strengths of VoIP telephone services is their costs. They have been becoming a relatively less expensive way of making and receiving telephone calls in comparison to telephone calls made through the POTS. However, tracing of call origins available in POTS for location-based services such as dispatching emergency services and law enforcement has not been made available in VoIP networks due to the size and constantly changing nature of VoIP networks and portability of VoIP devices.